Jornada Trails

by Bill Schlesinger, Duke University

The Jornada Basin LTER site has become an important laboratory for the development and testing of remote sensing technologies in arid landscapes. Last year, the Jornada was chosen to provide field measurements to validate simultaneous aircraft measurements using new, experimental remote sensing instruments. These sensors will help refine those that will be carried on a new generation of satellites in the NASA-Earth Observing System (EOS).

The field campaign, known as PROVE, allowed NASA scientists to compare their measurements of greenness, leaf area index, and plant biomass to known quantities measured by LTER and USDA scientists. This critical project will assure the accuracy of MODIS—a new multispectral sensor that will be carried on the EOS-AM platform in 2000.

Earlier, Jornada Trails (October 1996) reported on the JORNEX project, funded by the global change research program of the U.S. Department of Agriculture. JORNEX seeks to quantify land surface hydrology and energy balance in the heterogeneous landscapes of the Jornada Basin. This program also couples aircraft measurements of surface reflectance properties to our on-site measurements of surface energy flux and vegetation properties.

Data from JORNEX can be compared to satellite remote sensors, including LANDSAT, AVHRR, and GOES, improving the use of these instruments to monitor the spread of deserts throughout the world. In 1998, the JORNEX campaign will make comparative studies of the Sevilleta and Central Plains LTER sites.

The JORNEX project benefits from ongoing research by LTER investigator Vince Gutschick of New Mexico State University. For the past several years, he has examined the physiological controls on plant transpiration in the various habitats of the Jornada basin. Field measurements of individual plants are compared to simultaneous areal estimates from eddy-flux towers.

Further coverage of PROVE can be found in the July/August 1997 issue of The Earth Observer, published by NASA and reproduced on their website: http://eospso.gsfc.nasa.gov/.

Two of the Jornada LTER’s principal investigators have recently traveled abroad to present the results of their research to international audiences.

In September 1997, Kris Havstad spoke to the International Workshop on Rangeland Desertification, held at Reykjavik, Iceland. His paper was entitled "Rangelands, Degradation, and Nutrients."

In March of this year, Bill Schlesinger traveled to Lisbon, Portugal, where he spoke to a conference organized by the Luso-American Development Foundation (FLAD). His paper, entitled "Global Change, Desertification, and the Biogeochemistry of Arid Lands," was the keynote for a workshop to foster new studies of desertification in southeastern Portugal.

Congratulations are overdue to John Anderson! Last year, the New Mexico State University chapter of the Society of Sigma Xi honored John for his outstanding support of field research program at the Jornada LTER. All those who have visited our site know just how essential John is to the day-to-day operations and the long-term continuity and integrity of the site and its data management.

The Jornada LTER is also honored that Barbara Nolen received the 1997 Collaborator of the Year award from the USDA/ARS Natural Resources Institute in Beltsville, Maryland. This award recognized Barbara for her outstanding research collaboration in airborne remote sensing research in the PROVE and JORNEX campaigns at the Jornada.

Be sure to register for the annual Friends of the Jornada Symposium to be held at New Mexico State University on Thursday, July 16, 1998. A full day of informal research presentations will be followed by the traditional, and now famous, evening barbecue at the USDA Headquarters Ranch.

This is the Eighth Annual Symposium, and we expect that it will continue to provide a lively exchange of ideas and data on the Chihuahuan Desert environment. A registration fee of $10 covers the costs for refreshment breaks during the symposium as well as the evening barbecue.

For information or to register, contact:

Kris Havstad

USDA/ARS Jornada Experimental Range

Box 3JER, New Mexico State University

Las Cruces, N.M. 88003

by Kris Havstad, New Mexico State University

The 1998 Federal appropriation to the USDA included funds to design a new building for the headquarters of the Jornada Experimental Range. Located on the NMSU campus, this building will also house the Jornada LTER site office and provide space for several investigators in the Jornada LTER program.

During 1998, scientists and staff from the Jornada will be actively engaged in planning all aspects of this 29,000 square-foot research facility. An architectural and engineering firm from New Mexico has been selected to design the building and oversee all phases of construction. It is expected to be occupied in 2000.

Deb Coffin joined the USDA/ARS research unit at the Jornada Experimental Range as a range ecologist in January, 1998. Previously, Deb was a faculty member at Colorado State University, where she was a long-time participant in the Central Plains LTER project.

Deb is internationally recognized for research in rangeland plant ecology and simulation modeling. She has developed a unique model to explain vegetation dynamics in the shortgrass steppe, incorporating individual plant activities within the confines of the physical environment.

As a range scientist with the USDA, Deb will join the Jornada LTER research team and collaborate with the Sevilleta LTER site. Her general objective will be to synthesize small-scale, mechanistic studies of individual plants, populations, and communities into a predictive model of vegetation change. The model will integrate multiple levels of vegetation response with environmental factors, including disturbance, climate and soils. This spatially-interactive model will operate from the patch to the landscape and regional-scale, and will have both conceptual and simulation elements.

Deb can be reached by email at dcoffin@nmsu.edu.

Jornada Trails is proud to recognize the accomplishments of Dr. Jim Reynolds of the Department of Botany at Duke University. No stranger to New Mexico State University, Jim has worked at the Jornada for more than 20 years. He was involved in early studies of the productivity and growth of creosotebush during the International Biological Program.

As part of his current efforts, Jim is developing simulation models to predict desert ecosystem function at scales ranging from individual plants to entire landscapes. A patch model, known as the Patch Arid Lands Simulator (PALS), was recently used to predict the fate of soil moisture in small plots of grassland, shrubland and bare soil at the Jornada. A Regional Arid Lands Simulator (REGALS) will extend the predictions of the patch model, recognizing the hydrologic connections between different units of the landscape.

Working with Ross Virginia of Dartmouth College, Jim has also led a variety of field studies in the Jornada Basin. One recent study used rainfall exclusion shelters to test whether it is summer or winter-time precipitation that is the major driver of plant growth in the Jornada Basin. The paper, currently in press in Ecological Monographs, concludes that when shrub islands form in the desert, the shrubs become progressively less coupled to short-term fluctuations in precipitation and more resistant to long-term drought or climate shifts. Creosotebush subject to winter drought shifted its period of maximal activity to the summer period, taking advantage of seasonal differences in resource availability.

Reynolds has active collaborations with researchers at Carnegie Mellon University to develop an Integrated Assessment Model of desertification. He also is funded by the Inter-American Institute, which fosters collaboration and comparative research between North, Central, and South American.

Barrow, J. R., K. M. Havstad, and B. D. McCaslin. 1997. Fungal root endophytes in fourwing saltbush, Atriplex canescens, on arid rangelands of Southwestern USA. Arid Soil Research and Rehabilitation 11: 177-185.

Barrow, J. R., K. M. Havstad, J. Hubstenberger, and B. D. McCaslin. 1997. Seed-borne fungal endophytes on fourwing saltbush, Atriplex canescens. Arid Soil Research and Rehabilitation 11: 307-314.

Brisson, J. and J. F. Reynolds. 1997. Effects of compensatory growth on population processes: A simulation study. Ecology 78: 2378-2384.

Connin, S. L., R. A. Virginia, and C. P. Chamberlain. 1997. Isotopic study of environmental change from disseminated carbonate in polygenetic soils. Soil Science Society of America Journal 61: 1710-1722.

Estell, R. E., E. L. Fredrickson, D. M. Anderson, K. M. Havstad, and M. D. Remmenga. 1998. Relationship of tarbush leaf surface terpene profile with livestock herbivory. Journal of Chemical Ecology 24: 1-12.

Herman, R. P. 1997. Shrub invasion and bacterial community pattern in Swedish pasture soil. FEMS Microbiological Ecology 24: 235-242.

Herrick, J. E., K. M. Havstad, and D. P. Coffin. 1997. Rethinking remediation technologies for desertified landscapes. Journal of Soil and Water Conservation 52: 220-225.

Kerley, G. I. H., W. G. Whitford, and F. R. May 1997. Mechanisms for the keystone status of kangaroo rats: graminivory rather than granivory? Oecologia 111: 422-428.

Marticorena, B., G. Bergametti, D. A. Gillette, and J. Belnap. 1997. Factors controlling threshold friction velocity in semiarid and arid areas of the United States. Journal of Geophysical Research 102: 23277-23287.

Monger, H. C., D. R. Cole, J. W. Gish, and T. H. Giordano. 1998. Stable carbon and oxygen isotopes in Quaternary soil carbonates as indicators of ecogeomorphic changes in the northern Chihuahuan desert. Geoderma 82: 137-172.

Mun, H. T. and W. G. Whitford. 1998. Change in mass and chemistry of plant roots during long-term decomposition on a Chihuahuan Desert watershed. Biology and Fertility of Soils 26: 16-22.